Boss has had at least three envelope followers, or "automatic wahs". I have the first one, which was called a "Touch Wah" (TW-1). Later they released a unit called the "Auto-Wah 2" (I think). First, I should say that the "Touch Wah" was pretty great as is, so a straight ahead rehash would not have attracted me. However, the AW-3, as I have heard (and by the way, I think there are MP3 demonstrations online somewhere - maybe here), offers several really great twists on the usual theme, not to mention higher quality. For one thing, a Boss controller foot pedal (which I already have, so that's another plus) will put the filter in manual mode, which is essentially a regular wah-wah. It has a special mode that has human vowel sounds. I'm not sure what technically occurs to create the sound but it is appealing. Furthermore, it has dedicated guitar and bass inputs. I have used my old TW-1 with both guitar and bass with *no* dedicated inputs, but there are some difficulties there which this overcomes. There is also a tempo type mode that lets the effect do it's thing in rhythm, which is like having a phase shifter "spin" to the beat (accept this is like LFO control of the filter. More greatness. Great specs, great sound. I think the features are the best. I gave Quality and Value each a 4, because since I don't own it, I can't predict the future. Nevertheless, although I mainly use multi-effects, none of my several Boss floor effects has ever done anything but work like the day I got it. So, while I lean towards multi-effects units, once in awhile a single effect is so good at what it does, I go ahead and place it in the signal path. This is one of those times. I also want their new phaser (PH-3), because it is literally amazing how hard it is to find a great phase shifter in a multi-effects unit. I've found a number of good flangers in the multi-effects, but for some reason phasers are illusive. Seems like the PH-3 is everything I need in that realm, just as the AW-3 is.

Feature:
It has tons of different combinations of sounds that are easy to create. The worst part is when the battery runs out.

Quality:
its very durable and has good quality

Desirability:
You dont HAVE to have it compared to some other wah pedals, but it is a fun box if your just messin' around.

Sound:
This pedal is OK. If your into funky solos, this is not for you. It is mainly for any songs that require wah the entire way.

Overall:
Overall this pedal is decent. Not exactly Eric Clapton pedal, but its pretty fun to play with